Here is a Hydro_star, built near 7 years ago.
Never did like it too much and the costs were very high for my first build.
Inside is exactly what the first set of plans instructions have with the recommended parts.
The water level switch, the wound magnetic toroid, large tube diameter but only 5-6" long with a very tight precision gap.
All the PVC rings made and mountings assembled just like the instructions.
I do not recommnd the short tube_set. If you try the Hydro_star make a real large one.
Also still have the first circuit that did not work.